Wednesday, April 25, 2001

What happens after Lasik surgery?

Emory researcher reveals effects on cornea three years after procedure

Emory Eye Center researcher Henry Edelhauser, Ph.D. and co-workers have completed a three-year study on Emory University Eye Center patients who underwent a laser in situ keratomileusis (LASIK) procedure, a refractive surgery to correct eyesight.

The patients were evaluated to ascertain the long-term effects of such surgery on the corneal endothelium, the cells that line the inside of the cornea.

Sometimes referred to as the "window to the world," the cornea is the transparent covering over the eye.

"The follow-up study found that LASIK did not alter the corneal endothelium in patients studied three years postoperatively," says Edlehauser.

The report by Edelhauser and others* was recently published in the American Journal of Ophthalmology (January 2001) and was the issue's lead article.

The study marks the first long-term study of the important corneal endothelium, which could be affected by the popular procedure to correct myopia.

"This study is significant because it was the first to examine the long-term effects on the corneal endothelium in LASIK patients postoperatively," says Edelhauser, a professor in the Emory University School of Medicine.

Beginning in 1998 at Emory University, the study focused on 98 eyes of 65 patients. They were examined postoperatively and at 35 to 37 months after the procedure.

Patients ranged from 29 to 66 years of age, and 83 percent of them had a history of contact lens use prior to their surgeries.

Their corrections ranged from 2.25 to 14.5 diopters of myopia, that being from mild to more profound nearsightedness.

Results showed that LASIK "had no significant effect on central corneal endothelial cell density or the percent of hexagonal cells 3 years after surgery," according to the report.

Further, there was no significant change in the mean endothelial cell density or the percent of hexagonal cells, which comprise a major portion of endothelial cells.

The study found also found that when patients stopped wearing their contact lenses following surgery, the condition of their endothelium improved. The hexagonally-shaped endothelial cells are typically altered or damaged by diabetes and such conditions as wearing contact lenses.

The study's findings may put to rest any fears of physiological damage that some patients may have about the widely performed surgery.

In 2000, according to FDA reports, some 800,000 to 1.4 million Americans underwent laser refractive surgery, with those numbers increasing each year up from 210,000 in 1997.

Others who participated in the report included Michael J. Collins, MD; Jonathan D. Carr, MD; R. Doyle Stulting, MD, PhD; Ramzy G. Azar, MPH; George O. Waring III, MD; Robert E. Smith, MD; and Keith P. Thompson, MD.